The present invention relates generally to a charged particle spectrometer. More particularly the invention relates to an ion spectrometer having a lens system configured to extract from a sample ionized atomic components having well controlled energy and also to provide precise spatial manipulation of the various ion beams, enabling highly sensitive detection of the ionized atomic components. Improvement of signal to noise ratio is also achieved by exciting the atomic components to autoionization states before performing energy and angular refocusing time of flight (hereinafter, "EARTOF") mass spectrometric analysis.
Significant advances have been made in the quantitative analysis of atomic components in a sample. For example, resonance ion spectrometers have demonstrated considerable sensitivity for the detection of atoms of a predetermined component. (See, for example, U.S. Pat. Nos. 4,442,354 and 3,987,302 (Hurst et al.) and U.S. patent application Ser. No. 691,825, which are incorporated by reference herein). In practice, however, these previous resonance ion spectrometers still have significant limitations in terms of achieving sensitivities in the part per trillion range because of severe difficulties encountered in discriminating low level signals to be measured from noise made up of competing, undesired and extraneous signals.